Rationalization of microscopy in the detection of Neisseria gonorrhoeae in women.

This study looks at the sensitivity of microscopy in the diagnosis of Neisseria gonorrhoeae (NG), the effect of microscopy on time to treatment of NG and the added value of microscopy in the management of gonorrhoea. Women diagnosed with NG at an inner city genitourinary (GU) medicine clinic between August 2005 and July 2006 were identified and the notes reviewed. There were 103 women who were culture positive for NG. The sensitivity of microscopy was 38%. Microscopy is a point of care test (POCT) and in this group, it facilitated the treatment of 19% (n=20) of cases of NG infection at the first visit to a GU medicine service. If a POCT is not available, this would result in delayed treatment (32% of patients waited longer than 14 days and 3% did not return for treatment). In total, 29% of women did not return for test of cure, therefore confirming that effective first-line therapy is essential in the treatment of N. gonorrhoeae.

Molecular testing (strand displacement assay) for identification of urethral gonorrhoea in men: can it replace culture as the gold standard?

The objective was to evaluate the performance of Becton Dickinson's BD Probe Tec(TM) (BDPT) strand displacement amplification (SDA) test for the detection of Neisseria gonorrhoeae on urethral specimens from men with urethritis compared with conventional culture and to show that SDA improves the diagnostic yield of gonorrhoea infections (GC). Anonymized retrospective testing of stored urethral swab samples from men attending genitourinary services in East London was performed using SDA. The prevalence of GC culture positive infections in this sample was 20/152 (13%). The sensitivity, specificity, positive predictive value and negative predictive value for the BDPT-SDA system compared with culture were 100%, 95%, 77% and 100%, respectively. In this study population, the BDPT-SDA assay was a highly sensitive and specific test for the diagnosis of N. gonorrhoeae from urethral swabs in men. Therefore, SDA can be used to complement culture in the diagnosis of N. gonorrhoeae infection. No ethics committee approval was obtained as all samples were anonymized.

Dark ground microscopy and treponemal serological tests in the diagnosis of early syphilis.

OBJECTIVES: To evaluate the use of dark ground microscopy (DGM) and treponemal serological tests in the diagnosis of primary (PS) and secondary (SS) syphilis. METHODS: A retrospective case note review of patients with early syphilis who attended our department between January 2001 and December 2002. Data were collected on demographics, results of treponemal serology and DGM. RESULTS: 50 individuals had PS and 36 individuals had SS. DGM was performed in 31/50 (62%) of PS cases and this was positive in 97%. In 17 (34%) cases of PS, treponemal EIA was negative initially. DGM was performed on 13 of these, all of which were positive. Therefore, EIA had a sensitivity of 57% when compared to DGM. In 27 patients where EIA-IgM was performed, this was positive in 22 (81%), of which 12 were EIA negative on initial screening. All SS cases had positive EIA. DGM was performed in 19/36 (52%) of SS cases and was positive in 16/19--that is, a sensitivity of 84% when compared to EIA. The major reason why DGM was not performed in the cases of PS was that herpes was the presumed diagnosis and in SS the rash was attributed to other causes. CONCLUSIONS: DGM is a rapid and sensitive test while EIA takes time for results and is less sensitive in PS. EIA-IgM is a useful adjunct in PS. DGM allows immediate diagnosis, treatment, and partner notification preventing further transmission. Genitourinary medicine clinics should have trained staff to perform DGM on all anogenital ulcers and suspected syphilitic lesions.